The RSS Scatterometer L2B type orbit files are available in the Qscat_wind_vectors and Seawinds_wind_vectors directories. The following subroutines can be used to read these scatterometer files. Description of file format is located in each subroutine and is described at www.remss.com IDL get_scat_orbit_v03.pro and get_scat_orbit_v04.pro Matlab get_scat_orbit_v03.m and get_scat_orbit_v04.m Fortran get_scat_orbit_v03.f and get_scat_orbit_v04.f The file format of SeaWinds and QuikSCAT RSS Ku-2001 files is identical. The file names are changes (v03 or v04) so these routines are the same and will read data files from both instruments. To determine if your program is working correctly, you can check the data with those listed below. Download either: SeaWinds file seawinds_wind_vectors\01000to01999\winvec_01867_v03.dat or QuikSCAT file qscat_wind_vectors\04000to04999\winvec_04741_v04.dat Set your program to write out the data for scan lines 1378 to 1382 for SeaWinds or 1172 to 1176 for QuikSCAT and WVCs 55 to 60 for SeaWinds or WVCs 18 to 23 for QuikSCAT. Fortran (1-BASED) code for the write command would look like: do iscan=1378,1382 !1378,1382(seawinds) or 1172-1176(qscat) do icel=55,60 !55,60 (seawinds) or 18,23(qscat) if(iclass(icel,iscan).le.1) cycle write(*,'(2i5,7f8.2,i4,f8.2)') iscan,icel, . xlat(icel,iscan),xlon(icel,iscan), . winal(iselect(icel,iscan,icel,iscan), . phial(iselect(icel,iscan),icel,iscan), . sosal(iselect(icel,iscan),icel,iscan), . wingcm(icel,iscan),dirgcm(icel,iscan), . irain_scat(icel,iscan),rad_rain(icel,iscan) enddo enddo SeaWinds output (REV 1867) is: iscan icel xlat xlon wspd wdir sos gcm gcm scat amsr wspd dir flag rain 1378 55 -34.31 109.22 9.60 105.00 4.06 7.58 60.00 1 1.10 1378 56 -34.26 108.93 6.38 7.50 2.88 7.77 57.00 1 0.30 1378 57 -34.20 108.69 6.23 10.50 2.16 7.72 52.50 1 0.10 1378 58 -34.15 108.42 6.30 25.50 2.22 7.73 49.50 1 0.10 1378 59 -34.09 108.13 6.77 36.00 1.64 7.82 46.50 0 0.10 1378 60 -34.03 107.88 7.11 40.50 1.44 7.84 42.00 0 0.10 1379 55 -34.52 109.13 6.50 16.50 3.12 7.67 54.00 1 0.30 1379 56 -34.47 108.85 6.27 18.00 2.34 7.71 52.50 1 0.10 1379 57 -34.41 108.58 6.79 30.00 2.74 7.64 49.50 1 0.50 1379 58 -34.35 108.32 7.18 34.50 1.82 7.60 46.50 0 0.10 1379 59 -34.30 108.05 7.69 43.50 0.86 7.65 43.50 0 0.00 1379 60 -34.25 107.82 7.84 46.50 0.92 7.60 43.50 0 0.00 1380 55 -34.73 109.04 5.98 12.00 2.06 7.76 49.50 1 0.30 1380 56 -34.67 108.76 6.67 34.50 2.56 7.66 48.00 1 0.30 1380 57 -34.63 108.52 7.63 48.00 2.02 7.54 48.00 0 0.30 1380 58 -34.58 108.25 7.99 49.50 1.30 7.45 45.00 0 0.10 1380 59 -34.53 107.98 8.03 49.50 1.06 7.40 43.50 0 0.00 1380 60 -34.46 107.72 8.00 46.50 0.98 7.37 45.00 0 0.00 1381 55 -34.96 108.97 6.72 30.00 2.30 7.82 45.00 1 0.30 1381 56 -34.91 108.71 7.48 42.00 1.64 7.57 45.00 0 0.10 1381 57 -34.86 108.42 8.02 45.00 1.28 7.41 45.00 0 0.10 1381 58 -34.80 108.17 8.28 45.00 0.94 7.23 45.00 0 0.00 1381 59 -34.74 107.91 8.30 45.00 0.90 7.15 45.00 0 0.00 1381 60 -34.69 107.65 8.09 49.50 1.02 7.16 45.00 0 0.00 1382 55 -35.18 108.87 7.41 33.00 1.54 7.63 43.50 0 0.10 1382 56 -35.12 108.62 7.72 36.00 0.80 7.39 43.50 0 0.10 1382 57 -35.07 108.34 7.72 40.50 0.80 7.22 45.00 0 0.00 1382 58 -35.02 108.07 7.74 43.50 0.94 6.98 45.00 0 0.00 1382 59 -34.96 107.82 7.71 45.00 1.00 6.91 46.50 0 0.00 1382 60 -34.91 107.57 7.49 45.00 1.18 6.95 46.50 0 0.00 QuikSCAT output (REV 4741) is: iscan icel xlat xlon wspd wdir sos gcm gcm scat rad wspd dir flag rain 1172 18 9.52 150.50 4.13 294.00 1.48 4.80 292.50 0 0.00 1172 19 9.55 150.28 4.43 298.50 1.38 4.70 294.00 0 0.00 1172 20 9.59 150.05 4.89 304.50 1.78 4.60 294.00 0 0.00 1172 21 9.63 149.82 5.85 1.50 4.32 4.59 295.50 1 0.10 1172 22 9.66 149.59 8.28 288.00 3.44 4.65 295.50 1 0.30 1172 23 9.70 149.36 8.82 294.00 3.00 4.69 297.00 1 2.70 1173 18 9.29 150.44 4.23 297.00 2.20 4.83 294.00 0 0.00 1173 19 9.34 150.21 4.19 295.50 2.24 4.77 294.00 0 -999.00 1173 20 9.38 149.98 4.71 297.00 2.16 4.69 295.50 0 0.10 1173 21 9.41 149.75 6.14 292.50 3.74 4.70 295.50 1 0.10 1173 22 9.45 149.54 7.79 291.00 3.88 4.72 297.00 1 8.00 1173 23 9.48 149.30 7.27 358.50 3.58 4.75 297.00 1 13.30 1174 18 9.10 150.42 5.34 294.00 2.26 4.88 294.00 1 0.00 1174 19 9.16 150.14 5.69 286.50 2.86 4.85 294.00 1 -999.00 1174 20 9.19 149.84 6.21 283.50 3.08 4.81 295.50 1 0.10 1174 21 9.20 149.66 7.00 286.50 2.56 4.79 295.50 1 7.70 1174 22 9.24 149.47 7.76 289.50 2.68 4.78 297.00 1 10.40 1174 23 9.27 149.24 6.24 1.50 3.34 4.78 297.00 1 13.30 1175 20 8.95 149.77 5.73 292.50 2.28 4.88 295.50 1 -999.00 1175 21 8.98 149.63 6.80 288.00 3.36 4.86 297.00 1 0.10 1175 22 9.02 149.41 7.50 283.50 2.58 4.83 297.00 1 10.40 1175 23 9.06 149.19 7.20 286.50 3.26 4.81 297.00 1 0.10 1176 19 8.70 150.02 4.93 297.00 2.26 4.88 295.50 0 0.00 1176 20 8.73 149.97 4.48 303.00 1.20 4.87 297.00 0 -999.00 1176 22 8.82 149.25 4.79 294.00 1.34 4.82 298.50 0 0.10 1176 23 8.84 149.15 4.44 294.00 1.70 4.80 298.50 0 0.10 Note that the routines return -999.0 for radiomter rain rates when there is no collocated TMI or SSM/I data. If you have any questions regarding these programs or the RSS binary data files, contact RSS support: http://www.remss.com/support The data files, once decoded contain: ATIME is the 21 character time string, format: YYYY-DDDTHH:MM:SS.sss PHI_TRACK is the direction of the subtrack velocity vector relative to north XLAT is the geodetic latitude (-90 to +90) XLON is the east longitude (0 - 360) ICLASS indicates the expected quality of the vector retrieval ICLASS=0 denotes no retrieval was done (either no observations or only one flavor of observation) ICLASS=1 denotes 2 flavors of observations in wind vector cell ICLASS=2 denotes 3 flavors of observations in wind vector cell ICLASS=3 denotes 4 flavors of observations in wind vector cell We suggest using just cases for which ICLASS.GE.2 NUM_AMBIG is the number of ambiguites (0 to 4) ISELECT is the selected ambiguity (0 to 4) IRAIN_SCAT is the rain flag derived from the scatterometer measurements IRAIN_SCAT=1 indicates rain WINAL is the wind speed for the various ambiguities PHIAL is the wind direction for the various ambiguties (oceanographic convention) SOSAL is the normalized rms after-the-fit residual of the observation minus model sigma-nought. Large SOSAL values indicate the observations did not fit the geophysical model function. We suggest discarding observations for which SOSAL.GT.1.9. WINDS is the smoothed version of the selected wind, WINAL(ISELECT) PHIWS is the smoothed version of the selected wind, PHIAL(ISELECT) WINGCM is the general circulation model wind speed used for nudging (either NCEP or ECMWF) DIRGCM is the general circulation model wind direction used for nudging (either NCEP or ECMWF) RAD_RAIN is the TMI or SSMI columar rain rate (rain rate times rain column height, km mm/hour) RAD_RAIN=-999 no TMI or SSMI rain avaliable RAD_RAIN=0 no rain RAD_RAIN=0.1 possible rain RAD_RAIN=0.2 through 25.4 definite rain and the given value is the columnar rain rate "no rain" means no rain was detected within +/- 50 km and +/- time given in MIN_DIFF. "possible rain" means some rain was detected within +/- 50 km and +/- time given in MIN_DIFF. "definite rain" means rain was detected within +/- 25 km and +/- time given in MIN_DIFF. We suggest discarding observations for which RAD_RAIN.GT.0.15 MIN_DIFF is the time difference in minutes between the scatterometer and the collocated radiometer. A value of 255 means that no radiometer observation was collocated within 254 minutes of the scatterometer. NUDGE_NCEP NUDGE_ECWMF Each data file contains two INTEGER(1) variables at the end of the file. Both variables supply information on which GCM was used for the nudging field. The first variable shows if NCEP data were used (0=used, 1=not used), and the second shows if ECMWF data were used (0=used,1=not used). Since GCM data are tri-linearly interpolated to the QuikScat data, it is possible that one of each maps was used. If both ECMWF and NCEP data were missing for the required orbit, the orbit is not processed since no nudging field would be available. It is important to not use the data if the quality is suspect. We recommend the following conditions be satisfied for the **very best** quality data: ICLASS(icel,iscan).ge. 2 (this would omit all outer swath data) SOSAL(1,icel,iscan).le. 1.9 (yes, we mean the SOS of the lowest ambiguity) IRAIN_SCAT(icel,iscan).ne. 1 MIN_DIFF(icel,iscan).le. 30 .and. RAD_RAIN(icel,iscan).le. 0.15 The SeaWinds dataset contains several gaps. The following are known gaps: SeaWinds revs: QuikScat revs: 1724-1725 2146 2171 1895-1901 2793 2810 2241-2242 3068 3070 2396-2397 5627 5636 2774 6217 6218 2877 7356 7385 3173 9859 9907 3382-3395 10667 10694 3471 12572 12599 3476-3478 14306 14329 3647-3648 15831 15836 3786 16492 16504 3871 17788 17807 4453 20385 20389 22028 22029 23411 23423 26722 26729 36418 36426 36821 36855 38524 38527 40113 40115 40619 40621 44086 44096 46943 46962 49149 49190 49296 49302 53168 53196 Official information on gaps and the cause of missing data can be found at http://podaac.jpl.nasa.gov/seawinds/seawinds_prob.html#gaps The date and time information for each rev# is provided in the SEAWINDS_INFO.txt or QUIKSCAT_INFO.txt files The columns in this file represent: Rev #, # of good WVC rows, EQCROSSDATE, EQCROSSTIME, EQCROSSLONG, ORBITPERIOD If you have any questions regarding these programs or the RSS binary data files, contact RSS support: http://www.remss.com/support